Many motor home owners tow an automobile behind their motor home. The automobile is used for short local trips when the motor home owner arrives at his destination. The automobile has a self contained braking system, that is pedal activated.
Most jurisdictions require a braking system on the towed vehicle that cooperates with the braking system on the motor home. There are no commercially viable systems for connecting the braking system of a motorhome to a vehicle being towed to allow simultaneous application of the brakes of both vehicles. This has resulted in many motor home owners towing automobiles without an operative braking system on the towed vehicle, in contravention of the law.
What makes this application difficult is that the automobile towed by the motorhome has its own self contained braking system. Usually the system is a closed hydraulic system with a master cylinder that is operated by an operator depressing the brake pedal. Typically, a vacuum booster is incorporated between the brake pedal and the master cylinder which employs vacuum drawn from the intake manifold of the vehicles engine to assist the braking action.
Attempts have been made, in the past, to operate the braking system of a towed vehicle where the vehicle towed has its own self contained braking system. U.S. Pat. No. 4,398,771 which issued to McCurry et al, discloses a braking system for a towed vehicle. U.S. Pat. No. 2,674,349 which issued to Phillips, discloses a brake connection between two vehicles which requires the hydraulic circuit of the vehicle being towed to be rerouted. U.S. Pat. No. 4,756,390 to Leon Meadows, discloses a vacuum connection system between two vehicles which requires the use of long vacuum lines. The drawback of using such long vacuum lines is that they are subject to deterioration and perforation which leads directly to a loss of braking effectiveness. Such a system also experiences an unacceptable lag time for the brakes of the towed vehicle to be applied after the brakes of the towing vehicle have been applied.